Whatever you use as pipe, you will want emitters instead of holes. Their purpose is to make the same amount of water drip out of each hole. PVC will work, or just about any type of pipe. You can also use flexible plastic tubing, sometimes called "orchard tubing," which I use as header line for drip tape. In orchards and vineyards, the irrigation setup has to last several years, so they use the tubing instead of drip tape. Here is a pic of one:
http://www.kobrandwineandspirits.com...irrigation.jpg